Question: Simplify to lowest terms. $\dfrac{63}{70}$
What is the greatest common factor (GCD) of 63 and 70? $63 = 3\cdot3\cdot7$ $70 = 2\cdot5\cdot7$ $\mbox{GCD}(63, 70) = 7$ $\dfrac{63}{70} = \dfrac{9 \cdot 7}{ 10\cdot 7}$ $\hphantom{\dfrac{63}{70}} = \dfrac{9}{10} \cdot \dfrac{7}{7}$ $\hphantom{\dfrac{63}{70}} = \dfrac{9}{10} \cdot 1$ $\hphantom{\dfrac{63}{70}} = \dfrac{9}{10}$